1. Field Of the Invention
The present invention relates to a blade for a rotary mower, the blade being formed so as to reduce noise generated during mower operation.
2. Prior Art
The problem of noise generated by rotary mower blades has been recognized, and blades previously have been designed to reduce such noise. An example of such a blade is disclosed in European Patent Application 0 300 642 A1, published on Jan. 25, 1989. This Application discloses a mower blade wherein each end portion of the blade is sharpened at its leading edge for cutting purposes, and wherein at its trailing edge, an upwardly extending vane is provided. The vanes are displaced inwardly from the outermost edges of their respective end portions.
The present invention represents an improvement over the mower blade disclosed in European Patent Application 0 300 642 A1. More particularly, the trailing edge of each end portion of the blade is provided with a notch. The edge of each notch extends in a direction substantially perpendicular to the longitudinal axis of the blade for a distance approximating half of the blade""s width. The notch edge then changes direction extending outwardly at an angle to the blade""s longitudinal axis until the notch edge reaches the outer edge of the blade. The trailing edges of the blade""s end portions adjacent the notches are bent upwardly, substantially along lines coextensive with the direction of the respective notch edges as the latter extend outwardly to the blade ends, to form an upwardly extending vane at each end of the blade adjacent a notch. A central portion of the blade is joined to the end portions by respective intermediate blade portions which are twisted relative to the blade""s longitudinal axis so as to form inclined surfaces which descend from the leading edges of the blade to the trailing edges.